Work to be initiated or completed in the ensuing year includes: 1) Extension of the present series of lateral infarcts to 10 animals. 2) Continuation of double ligation experiments, adding 3 additional animals to the 2 already completed to document VCG sensitivity to infarct extension. 3) A series of 5 reperfusions with lateral infarction to document VCG sensitivity to myocardial salvage. 4) A series of 10 animals with serial body surface recordings using a chronically implanted arterial snare, and series of 5 animals using acutely implanted snare and epicardial electrode grid to relate epicardial and body surface QRS. 5) Implement a pilot study on VCG infarct sizing in patients with acute myocardial infarctions.